@Test
public void testBuilders() throws Exception {
assertEquals("ds", pk1.getProjectId());
assertEquals("kind1", pk1.getKind());
assertTrue(pk1.getAncestors().isEmpty());
assertEquals("ds", pk2.getProjectId());
assertEquals("kind3", pk2.getKind());
assertEquals(parent1.getPath(), pk2.getAncestors());
assertEquals(pk2, IncompleteKey.newBuilder(pk2).build());
IncompleteKey pk3 = IncompleteKey.newBuilder(pk2).setKind("kind4").build();
assertEquals("ds", pk3.getProjectId());
assertEquals("kind4", pk3.getKind());
assertEquals(parent1.getPath(), pk3.getAncestors());
}